Periosteal chondroma of the rib: A case report

Figure 1 Computed tomography. A and B: Representative plain computed tomography showed a lobulated soft tissue mass on the right side of the T4/5 vertebra that measured about 47 mm × 28 mm in the transverse view and contained diffuse stippled calcification; C: The mass caused cortical scalloping of the right fourth rib, rim ossification (arrow), and narrowing of the myeloid cavity. Enhanced computed tomography showed mild enhancement of the mass.

Figure 2 Magnetic resonance imaging. A: T1-weighted magnetic resonance imaging in the transverse view showed a lobulated tumor on the right side of the thoracic vertebra; B and C: The lesion was bordered by a hypointense rim (arrow) and exhibited long T1 and T2 signals in the sagittal view on T1-weighted (B) and T2-weighted (C) imaging; D: Short tau inversion recovery imaging showed high signal intensity and mottling and patchy long T1 and short T2 abnormal signals within the mass; E: Enhancement was seen predominantly at the periphery of the lesion on post-enhanced images.

Figure 3 Hematoxylin-eosin staining results (× 200). The tumor consisted of a large amount of highly differentiated transparent cartilage and a mature trabecular bone structure. Most regional chondrocytes were differentiated and mature, and focal areas showed mild atypical and mucoid-like changes, consistent with a periosteal chondroma.